[BACKLOG-623] Update the extension point plugin to add remaining event metadata for transformations
	- Events now include the @SnmpTrapEvent annotations ( OID's according to the MIB file )
	- TransformationEvent also includes for each attribute the @SnmpVariable ( OID's according to the MIB file )
	- [CLEANUP] moved EventTypes enums within each of the event classes to a centralized class ( easier to maintain ); now each eventType also provides its own SNMP value (set in the enum)
Merge pull request #739 from pedrofvteixeira/BACKLOG-623

[BACKLOG-623] Update the extension point plugin to add remaining event m...